In a networked environment, such as the Internet, first-party content providers can provide information to user devices for presentation on resources, such as webpages, mobile applications, documents, other applications, and/or other resources. Additional third-party content can also be provided by third-party content providers for presentation on the user devices together with the information from the first-party content providers. A publisher may provide first-party content and third-party content on his or her resource. In one implementation, a first-party content provider can provide a search result interface in response to a search query from the user device, and third-party content can be provided for display on the search result interface. One challenge is determining the effectiveness of different content from a third-party content provider on different platforms (e.g., content provided for search result interfaces and for other web sites).